1. Field of the Invention
The present disclosure relates to an anchor pretensioner for a vehicle. More particularly, it relates to an anchor pretensioner which may safely protect an occupant by restricting a pelvis area of the occupant at an early stage of a vehicle collision.
2. Description of Related Art
In general, drivers, who use vehicles that become high graded in quality and large in size, are greatly interested in safety devices capable of safely protecting passengers as well as basic vehicle performance such as traveling performance, ride quality, and speed.
The safety devices for a vehicle, which are exemplified by a seat belt, an airbag, a steering safety shaft, and the like, are automatically operated at the time of a vehicle accident so as to maximally protect drivers and occupants, and are globally recognized as safety devices that need to be essentially installed in the vehicles.
Typically, the seat belt is formed of a high tensile fibrous material, and has a detachable buckle.
A spool, on which the seat belt is wound, is fixed to a side wall of a vehicle body, in order to improve convenience for a user, and serves to freely release or wind the seat belt.
The spool is rotatably installed on a frame, and configured to be restored to an original position using spring elastic force.
Meanwhile, a seat belt retractor has an impact sensor for temporally fixing a reel when the seat belt is instantaneously released from the reel while an upper body of the driver or the occupant is instantaneously moved forward when the vehicle is suddenly decelerated due to a head-on collision or the like.
However, on the contrary to the original object of the seat belt which restricts the driver or the occupant on the seat, there is a drawback in that a face of a user collides with a window or a steering wheel in an actual accident.
The reason is that there is a gap between the upper body of the driver or the occupant and the seat belt and the back of the seat immediately after the collision, and a device, which achieves safety of the driver or the occupant by eliminating the gap, is referred to as a pretensioner.
FIG. 8 illustrates an example of an anchor pretensioner in the related art.
The anchor pretensioner is mounted on a “B” pillar lower end or a seat of a vehicle, serves to restrict a pelvis area of the occupant at an early stage of a vehicle collision, and has a structure for axially drawing in a lap belt webbing.
For example, when a deployment signal is input from an Airbag Control Unit (ACU), a microgas generator (MGG) 200 is ignited, a piston 210 is moved along a cylinder 220 by explosive pressure, and consecutively, a cable 230 connected to the piston 210 is pulled, such that the cable 230 and the lap belt webbing 240 are connected by a connector 250 so as to restrict the pelvis area of the occupant.
In order to prevent the lap belt webbing from being withdrawn after maximally drawing in the lap belt webbing, a locking structure mounted on the piston 210 is operated against a load that is applied in the reverse direction by the occupant.
However, the anchor pretensioner in the related art has the following drawbacks.
Firstly, the cable and the connector of the pretensioner are exposed to the outside by 100 mm or more in a state in which the anchor pretensioner is mounted in the vehicle, and as a result, the anchor pretensioner in the related art is disadvantageous in terms of an external appearance (FIG. 9A).
Secondly, in a case in which a bellows made of rubber is applied to improve the external appearance when drawing in the pretensioner, the bellows hinders an operation of the pretensioner while being compressed when the pretensioner is drawn in, and as a result, a drawing amount is reduced (deviation occurs) (FIG. 9B).
Thirdly, when the occupant is moved forward due to the vehicle collision, a belt intersection angle is gradually reduced, and as a result, there is a problem in that the lap belt is caught in the belly (submarine phenomenon) (FIG. 9C and FIG. 9D).
Here, the intersection angle is increased when an initial mount position of the pretensioner is moved in a forward/downward direction of the vehicle, but it is difficult to increase the intersection angle because of a layout of the vehicle.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.